Wouldn't it be great to be fully retired before your 30th birthday?
Because they are engineered with a minimum design life of 25 years, it's common for the submarine cables that keep our world connected to experience this luxury.
Let’s talk about why, and what happens to cables after they reach retirement age.
The wet plant components of a cable are designed to have a specified failure rate during a 25-year period. Many warranties, permits, and landing licenses also commonly expire after 25 years. There’s nothing magic about 25 years, it’s just a commonly agreed upon number for setting these standards.
Cables may remain operational longer than 25 years, but they’re often retired earlier because they’re economically obsolete. They just can’t provide as much capacity as newer cables at a comparable unit cost, and are thus too expensive to keep in service.
In fact, while doing research for my SubOptic 2023 presentation earlier this year, I found that for repeatered cables retired from 2010-2022, the average lifespan was only 17 years.
When a cable is retired it could remain inactive on the ocean floor. Frequently, there are companies that are gaining the rights to cables, pulling them up, and salvaging them for raw materials.
In some cases, retired cables are repositioned along other routes. To accomplish this task, ships recover the retired cable and then re-lay it along a new path. New terminal equipment is deployed at the landings stations. This approach can sometimes be a cost-effective method for countries with small capacity requirements and limited budgets.
Some cables ease their way into their golden years by opting to partially retire. These cables—such as Columbus-II and Columbus-III—have partially retired but continue to have one segment still hard at work.
Just this past summer, the Japan-U.S. cable joined the partially retired club. So while most segments of Japan-U.S. are enjoying a great ocean view in retirement, the Hawaii-California segment remains hard at work for now.
Many cables laid during the late 1990s/early 2000s telecom boom days are nearing their 25th birthday and still going strong. Did these cables not save enough for retirement and have to work longer than expected? Not exactly.
These systems have benefitted from improvements in terminal equipment to massively boost their capacity. Without these advancements, these cables would have been economically obsolete years ago.
The chart below shows repeatered cable systems that are already over 20 years old.
It's likely that most of these will be retired by the end of this decade. The need to replace this older generation of cables partially explains why we are seeing a surge of investment in new submarine cable systems around the world. Just have look at all these planned cables.
Unless you’re filled with thin glass fibers and capable of long-distance information transfer, retiring in your 20s is not for you. You should probably stay at your current job.